Exhaust sounds different

[mr_maxime]

I've noticed that the exhaust started sounding different. Best I can hear it from is right behind the driver's seat. Only thing I've done recently is change from Castrol GTX to vr-1. I'm worried something might have come loose or broken.

https://youtu.be/HKcYTq7YXtI

[Bob635]

You might want to watch the video documentary on what happens to your Delorean as it ages 35 years.

Bob

I've noticed that the exhaust started sounding different. Best I can hear it from is right behind the driver's seat. Only thing I've done recently is change from Castrol GTX to vr-1. I'm worried something might have come loose or broken.

https://youtu.be/HKcYTq7YXtI

[David T]

You might want to watch the video documentary on what happens to your Delorean as it ages 35 years.

Bob

Check for exhaust leaks. The exhaust manifold gaskets commonly blow out.

[mr_maxime]

That's kind of what I figured. I couldn't think of a way of easily checking it though.

[opethmike]

Definitely a bad manifold gasket.

[David T]

You can tell by the sound if you have any experience. Other ways include looking for black sooting, feeling for air movement, missing nuts, etc. Basically if you think it is leaking it probably is. Another thing to check is the bonding of the rear window at the bottom, center. Press on the fiberglass. If it moves it is no longer attached to the glass and that lets in a LOT of noise. It can be one of the most fun jobs to do on a car. High probability of breaking the studs if you don't know what you are doing. My favorite way is to heat the nuts up to cherry red and let them cool. Heat a second time and then carefully unscrew the nuts. Works 99% of the time. Figure on resurfacing the manifolds. Only a machine shop can do that but it isn't expensive. You should also replace the studs. PJ Grady has a S/S kit. Expensive but well worth it for the next time! If you don't have a torch you should probably let a shop do the job. Pre-arrange with them so you can supply the parts, a gasket set and the studs and nuts. Verify they will send the manifolds out to be ground flat, that is important so the gaskets don't blow out again soon. The studs are metric so you will not be able to source them locally and the gaskets will be better than you can find locally if you get them from a D vendor.

[mr_maxime]

How critical is this to fix? The Delorean is my only car at the time so time consuming repairs like this aren't easy to do. I also don't know any shops nearby that could do it. I might have to arrange a trip to either dmch or dmcfl.

[David T]

[QUOTE=mr_maxime;210905]How critical is this to fix? The Delorean is my only car at the time so time consuming repairs like this aren't easy to do. I also don't know any shops nearby that could do it. I might have to arrange a trip to either dmch or dmcfl.[/QUO

The leaking and noise will get worse over time. Eventually it can damage the surfaces of the cylinder head by erosion. If you let it go that far you have to remove the heads and get them resurfaced as well, a much bigger job. In most States you will fail inspection. Any good shop should be able to do this job in a day or less.

[DMCMW Dave]

[QUOTE=David T;210907]

How critical is this to fix? The Delorean is my only car at the time so time consuming repairs like this aren't easy to do. I also don't know any shops nearby that could do it. I might have to arrange a trip to either dmch or dmcfl.[/QUO

The leaking and noise will get worse over time. Eventually it can damage the surfaces of the cylinder head by erosion. If you let it go that far you have to remove the heads and get them resurfaced as well, a much bigger job. In most States you will fail inspection. Any good shop should be able to do this job in a day or less.

I don't think I've EVER seen heads damaged due to this to the point of needing to be resurfaced. The manifolds, however, must be resurfaced any time you do this job.

If you take it to a local shop be really sure that they know what they are doing. Don't let them take shortcuts such as skipping the manifold resurface or only doing one side. Make sure that they are comfortable extracting broken studs and doing thread repair in blind holes. If the job is done incorrectly it won't last very long. If they run a drill or tap through a stud hole in the head you'll end up with coolant or oil leaks.

[mr_maxime]

Finding a good shop that I trust isnt all that simple. Iwouldnt be surprised to find someone that claimed to know what they were doing and didn't.